Ophthalmic aspirating/irrigating device

ABSTRACT

An ophthalmic aspirating/irrigating device incorporates a needle comprising two tubes disposed in close proximity and terminating close to one another at the distal end of the device. The distal end of the needle is insertable into an eye to be treated while the proximal end of one tube is connected to a syringe by way of a valve device. The valve device contains two one way valves, one of which provides passage only from the syringe to a discharge opening and the second of which provides passage only in the direction from the tube to the syringe. The valves are of the type comprising two flexible lips normally in contact with one another and separable by a pressure rise across the valve to present an orifice. The valves are disposed such that when the device is in a vertical position with the needle projecting downwardly, the orifice of the one valve is located at a distance of at most 1 mm below the level of the orifice of the other valve.

FIELD OF THE INVENTION

The invention relates to an ophthalmic aspirating/irrigating device.

BACKGROUND OF THE INVENTION

In the performance of some operations to the eye it is necessary toremove cortical fragments and/or other debris from behind the iris, suchaction being preferably followed by an irrigating action in whichirrigating fluid is introduced behind the iris to ensure that the placefrom which the cortical fragments had been removed is clear. Theinstrument which has been developed to perform this operation comprisesa syringe attached to a double needle having two passages one of whichis open at the proximal end to the barrel of the syringe and the otherof which is connectible at the proximal end to a source of supply ofirrigating liquid and the distal ends of the two passages are open andclose to one another. In operation of the aspirating/irrigating devicethe piston of the syringe is advanced and the distal end of the doubleneedle is introduced into the eye and maneuvered into the position inwhich the distal end of the needle is in the portion of the eyecontaining the cortical fragments and/or other debris. Irrigating liquidis allowed to flow into the eye cavity containing the debris and thepiston of the syringe is then withdrawn to draw the irrigating liquidcontaining the cortical fragments and/or other debris through the tubeconnected to the barrel of the syringe. It usually happens that at thefirst withdrawal of the plunger not all the debris is removed and it maybe necessary to remove the device from the eye several times so thatdebris which has been withdrawn from the eye may be discharged from thesyringe along with irrigating liquid, the needle then being re-insertedinto the eye to remove remaining debris. It has been found that thisaction may have to be performed as often as three or four times.

The repeated insertion of a needle into the eye is highly undesirableand it is an object of the present invention to provide anaspirating/irrigating device which requires only one insertion into aneye to remove all the debris and irrigate the eye.

SUMMARY OF THE INVENTION

In accordance with invention, an ophthalmic aspirating/irrigating deviceis provided having, in use, a distal end and a proximal end andcomprising a needle comprising two tubes disposed in close proximity,and terminating at one end close to one another at the distal end of thedevice, said one end of said tubes being insertable into an eye to betreated; and valve means connecting the other end of one tube to asyringe, said valve means comprising a first one way valve whichprovides passage only from the syringe to a discharge opening of thedevice and a second one way valve which provides passage only in thedirection from said one tube to the syringe, each of said valvescomprising two flexible lips normally in contact with one another andseparable by a pressure rise across the valve to present an orifice, andsaid valves being so disposed that when the device is in a verticalposition with the needle projecting downwardly, the orifice of saidfirst valve is located a distance of at most 1 mm below the level of theorifice of said second valve.

The invention also comprises the combination of a device as describedand a syringe to which the device is fitted.

Each one way valve may be formed as two flexible lips which are normallyin contact with one another and forming together an acute angle so thatthe lips can be moved apart by a pressure rise across the valve in onedirection and will be forced together by a pressure rise across thevalve in the other direction.

The two valves may be incorporated within a body having a straighttubular portion containing the valve providing one way access from theneedle tube to the syringe and a branch containing the valve providingone way access from the syringe to a discharge opening.

For a reason to be explained later it is important to locate the valvessuch that when the device is in a vertical position with the needleprojecting downwardly the tip of the valve providing passage only fromthe syringe to the discharge opening is located a distance below thelevel of the tip of the other valve providing passage only in thedirection from the needle tube to the syringe. Said distance may beabout 1 mm or less.

The straight tubular portion may be so arranged that the end adjacentthe downstream end of the one way valve in said straight portion is apush fit on the nozzle of a syringe while the other end is formed as aspigot which is a push fit on a socket carrying the needle.

For ease both of manufacture and assembly all the parts of the valvedevice may be moulded to be a push fit in one another.

BRIEF DESCRIPTION OF THE DRAWINGS

A practical embodiment of the invention is illustrated in theaccompanying drawings in which FIG. 1 shows a device according to theinvention fitted to a surgical syringe and FIG. 2 is a section of thedevice of the invention drawn to a much enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawings 1 denotes a syringe incorporating a barrel 2 and aplunger 3 loaded by a spring 4 fitted as an addition to the syringe sothat the plunger 3 tends to move to its withdrawn position. 5 denotes avalve device attached to the nozzle 6 of the syringe 1. 7 denotes asocket a press fit on the end of the valve device 5 remote from thatarranged to receive the nozzle 6 of the syringe. The socket 7 supportsthe inner tube 8A of a needle 8 which comprises said inner tube 8A andan outer tube 8B surrounding the inner tube 8A. The inner tube 8A whichis open at its distal end, i.e. the end remote from the socket 7, isthus connected through the socket 7 and by way of the valve device 5 tothe interior of the barrel 2 of the syringe 1. The outer tube 8Bterminates slightly short of the inner tube 8A at the distal end of theneedle 8 and is open to the interior of a sleeve 9 formed with a branchconnection 10 connectible to a supply of irrigating liquid. The valvedevice 5 incorporates two one way valves 11 and 12 so arranged that thevalve 11 provides passage only in a direction towards the syringe. Thenozzle 6 of the syringe 1 fits into the socket 13 provided in the valvedevice 5. The valve 12 is arranged in the branch of the valve device andis so arranged that it provides passage only in the direction from theinterior of the valve device to a discharge passage 14. Each valvecomprises two lips 15 of flexible material which come together at anacute angle and are arranged to be normally in contact with one another,being maintained in contact by their own resilience.

In practice, when the device is to be used on an eye it is fitted asdescribed to a surgical syringe and the branch connection 10 isconnected to a supply of irrigating fluid. The plunger 3 of the syringeis first advanced and the needle 8 is then inserted into the eye usuallywith the distal end in the space behind the iris where corticalfragments and other debris tend to gather. Irrigating fluid passesthrough the tube 8B in the annulus between the tubes 8A and 8B into saidspace behind the iris. On releasing the plunger the spring 4 withdrawsthe plunger and the suction in the barrel 2 causes the valve 11 to openi.e. the two lips 15 separate and irrigating fluid which is now fillingsaid space behind the iris and cortical fragments and other debris aresucked from the eye into the syringe barrel through the tube 8A. Whenthe plunger has been withdrawn to its fullest extent it is againadvanced compressing the spring 4. This time the rise of pressure in thebarrel 2 causes the lips 15 of the valve 11 to come together rapidlyalthough they tend to do so anyway by their own resilience as soon aspressure is equalized on both sides of the valve. At the same time therise of pressure on the upstream side of the valve 12 causes the lips 15of the valve 12 to open so that the irrigating fluid and fragments anddebris in the syringe are expelled through the valve 12 and out of thedischarge passage 14. Without removing the device from the eye theplunger may now be released for a second time so that irrigating fluidand other cortical fragments and debris which had not been removed fromthe eye in the first operation are withdrawn into the syringe barrel 2and then expelled as before through the passage 14. This operation maybe performed as often as is necessary until no more cortical fragmentsand debris remain in the eye. The device is removed from the eye onlywhen the operation is complete, i.e. when all cortical fragments anddebris are removed. The operation can thus be performed with only oneinsertion of the syringe into the eye.

It is sometimes found during use of the instrument when withdrawingirrigating liquid and any fragments of debris that the suction createdcauses the posterior chamber capsule of the eye, usually referred to asthe capsular bag, to be sucked against the orifice of the needle.Withdrawal of the liquid and contained fragments must be stoppedimmediately so that damage to the capsular bag does not occur. Thecapsular bag must then be moved away from the needle to clear the needleorifice. This cannot normally be done by merely depressing the plungerof the syringe because the rise of pressure would simply close the valve11 so that no pressure would be applied from within the needle, also theslight pressure of the irrigating liquid entering through the branchconnection 10 is sufficient to keep the capsular bag pressed against theneedle. To avoid such a happening the tip of the discharge valve 12 islocated a distance below the level of the tip of the inlet valve 11 anamount which is not more than 1 mm. By this expedient it is possible bymomentarily depressing the plunger by a minute extent 30 to generate asmall pressure wave which passes through the valve 11 before it has hadtime to close and, since the valve 11 is above the level of the valve 12and thus receives the pressure wave a small fraction of a second beforethe valve 12 receives the pressure wave, before the valve 12 has hadtime to open and nullify the effect. This extremely small rise ofpressure momentarily occurring within the tube 8A is sufficient to movethe capsular bag away from the orifice in the needle without damage tothe capsular bag. The operation of removing cortical fragments anddebris may then be continued.

The ophthalmic device of the invention particularly incorporating twovalves as illustrated has been found to be very effective because of thefeature that an extremely small pressure difference across each valvecauses it either to open or close according to the side on whichpressure is higher. There is thus immediate response by the valves tomovement of the piston 3 and also virtually no reverse flow through thevalves. Other types of valves tend to be slower in action and also topermit some amount of reverse flow so that cortical fragments and debrisremoved from the eye can be forced back into the eye. It may be remarkedthat the plunger withdrawal spring has been fitted to the syringe sothat the syringe may be operated with one hand. This is highly desirablein eye operations. The device may however be used without the additionof a plunger withdrawal spring.

I claim:
 1. An ophthalmic aspirating/irrigating device having, in use, adistal end and a proximal end and comprising a needle comprising twotubes disposed in close proximity, and terminating at one end close toone another at the distal end of the device, said one end of said tubesbeing insertable into an eye to be treated; and a valve assemblyconnected between the other end of one tube and a syringe including aplunger, said valve assembly comprising a first one way valve means,comprising two flexible lips normally in contact with one another andseparable by a pressure rise across the first valve means to present afirst orifice, for providing passage only from the syringe to adischarge opening of the device and a second one way valve means,comprising two flexible lips normally in contact with one another andseparable by a pressure rise across the second valve means to present asecond orifice and disposed relative to said first valve means such thatwhen the device is in a vertical position with the needle projectingdownwardly the orifice of said first valve means is located at adistance of at most 1 mm below the level of the orifice of said secondvalve means, for normally providing passage only in the direction fromsaid one tube to the syringe and for also providing passage of a smallpressure wave, produced by momentarily depressing the plunger of thesyringe, through the second valve means prior to the closing of saidsecond valve means and the opening of the first valve means.
 2. A deviceaccording to claim 1 wherein the two valves are incorporated within abody having a straight tubular portion containing the first valve and abranch containing the second valve.
 3. A device according to claim 2,wherein the straight tubular portion is so arranged that the endadjacent the downstream end of the one way valve in said straightportion is a push fit on a nozzle portion of the syringe while the otherend is formed as a spigot which is a push fit on a socket carrying theneedle.